Hey guys, I have a problem that's more of an annoyance than anything. My heater in my Corolla works great, but there's a noticeable gurgling sound that occurs every few minutes. I'll turn my car on and then turn the heat on to "LO." Within seconds, a 3-4 second long gurgling sound will occur. It sounds similar to sucking liquid through a straw, if that makes any sense. If I could locate it, it sounds like it's coming from deep behind the stereo deck, or from the engine compartment maybe (it's not loud, but noticeably audible). It will go away for a few minutes, then I'll hear a gurgle for about a second, and this behavior continues every 5 minutes or less as long as the heater is turned on.
What could be causing this sound, and is it something I can fix?
Thanks!
-M